Agriculture Reference
In-Depth Information
What They Need
Some microbes breathe air, just like us. They're called aerobic microbes. Other microbes
die in the presence of gaseous oxygen, so they live in places where there is none, such as
deeper in the soil. They're called anaerobic microbes, or anaerobes. Yet another group of
microbes called facultative anaerobes can actually switch their respiration depending on
whether or not there is sufficient oxygen present. The human pathogen
E. coli
belongs to
this last group, but so do many beneficial microbes, such as the yeast that makes bread.
In general, we want to promote the aerobic microbes in our soil because they tend to be
the beneficial ones. Anaerobic microbes are not bad in themselves, but the by-products of
their respiration and metabolism include hydrogen sulfide and other ingredients toxic to
plants and other soil life.
Microbes need water, some more than others. Bacteria in particular need a moist envir-
onment, whereas fungi can handle it a little bit drier. Some microbes need light. In fact,
some of them photosynthesize like plants. They all function best in their own specific tem-
perature range. They slow down when the soil freezes, some of them going right to sleep,
but many of them working right through the winter. As it warms up in the spring, more and
more of them wake up and get to work, just as the plants are waking up and need the ser-
vices of these tiny friends.
